This weekend I bought an '03 H2 with 26,000 miles.On the way homeit stalled while driving and when I restarted it the truck would not idle well and would eventually die. I had previously read the thread on this forum about the ignition switch going bad and immediatly noticed the symptoms.I had actually printed out the thread with part number. I ran to the GM parts dept and got a new switch and replaced it. After doing this the truck starts fine but almostimmediatly dies which I believe indicates I tripped the anti theft system. I did not unplug the harness on top of the key assembly only the ignition switch itself. I had to have it towed to the dealer and they are going to program the new switch tomorrow.

Just an FYI that you cannot just swap in a new ignition switch without a visit to the dealership. That was my experience anyway.

 

Also I noticed the replacement ignition switch had a different part number printed on it than the original. Perhaps it is an improved unit.Also the snap that locks it in place is gray instead of black like the original switch.

 

Ask the dealer what they did to program it.

I know on some GM's, you just turn the key on, shut the door,and walk away for about a half hour. The computer relearns the code in that time.

 

You wouldn't by any chance be falling for no bananna in your tailpipe would ya'?

Nah, seriously, the more i read, the more i find there's so many squirreley security things on these rides, I'd definitely hit the dealer up.. it's probably something simple...

Enjoy your truck! I just bought my 03' this weekend also... good find with the 26,000 miles.. I thought I had a find with my 29000 miles... there's still a few gems out there...

 

Dealership says it'sthe fuel pump thatdied... going to be $750+ to get it back on the road. Looks like the anti theft wasn't tripped after all.